1. Field of the Disclosure
The invention relates to the identification of breaths (e.g., for breath rate determination) based solely on the concentration of a gaseous molecular species, such as carbon dioxide, at or near the airway of a subject.
2. Description of the Related Art
Systems that monitor the concentration of carbon dioxide at or near the airway of a subject are known. In conventional systems, it may be difficult to accurately and/or precisely identify breaths based solely on this capnographic information. Typically, the concentration of level of carbon dioxide is monitored, and dips below an upper level corresponding to inhalations are counted as breaths. However, this technique is susceptible to counting false breaths caused by cardiogenic oscillations and other ineffective gas movements the breathing circuit.
Some conventional systems include additional sensors, such as flow and/or pressure sensors to enhance and/or facilitate identification of breaths. The addition of sensors to a system also increases the cost and/or is accompanied by other drawbacks.